This is an L57 in 243 serial 2xxx, probably with a non Sako barrel. Can anyone confirm that it really is a non-original barrel before I pull it off and replace it with a 308. Has these markings - which seem like 'WMo' or something like that, a brand name? someones initials? any clues would be helpful. No Sako stamp anywhere on it, no other markings beside cal. 243. also anyone any idea if going from 243 to 308 is going to require a recoil lug cross bolt? and if so where does one get them?